The present invention relates generally to an apparatus and method for transferring a workpiece and, in particular, to a modular lift and carry apparatus adapted for transferring large parts between successive work stations.
Automated transfer devices are used for moving a workpiece between different stations in a repetitive manufacturing process. Currently, most industrial transfers are either robotic devices or shuttle systems. In general, robotic transfers are used to provide reciprocable linear and/or arcuate movement between the successive work stations and are generally best suited for handling relatively small and lightweight parts. Moreover, robotic devices are generally impractical for use in multi-station successive transfer operations due primarily to their inability to transfer a plurality of successive parts in a single transfer operation. Therefore, large, bulky or heavy workpieces and multi-station processes typically require application of shuttle-type transfer systems.
Conventional shuttle transfers are generally quite massive and require significant floor space. Furthermore, conventional shuttle systems have the disadvantage of being installed in such a manner that they cannot be easily removed for repairs, access to the work stations for tooling changeover purposes and the like. In addition, shuttle systems have typically been designed for a specific transfer application and, as such, are generally not adapted for relocation to a different transfer application within a production facility.
Accordingly, it is a primary object of the present invention to overcome the disadvantage of the prior art and provide a workpiece transfer apparatus adapted to generate rectilinear vertical and horizontal movement for transferring a workpiece between successive work stations.
It is another object of the present invention to provide a transfer apparatus that is adapted to accept bulky, heavy and otherwise awkward workpieces while providing highly accurate part placement capability. Furthermore, the present invention is modular in construction for simple installation around pre-existing equipment. The universality of the modular components facilitates improved serviceability and durability as well as simple modification for accommodating numerous part transfer applications.
Another object of the present invention is to provide a transfer apparatus and method capable of selectively controlling the part placement characteristics through a relatively large and continuously variable range of rectilinear vertical and horizontal motion.
It is a further object of the present invention to provide an improved transfer apparatus capable of producing improved transfer speed and weight handling characteristics.
In accordance with the teachings of the preferred embodiment of the present invention, a "lift and carry" transfer apparatus is provided for transferring or "indexing" a workpiece between successive work stations in a multi-operation process. The transfer apparatus includes a modular support structure from which a generally elongated shuttle assembly is horizontally supported. A first drive mechanism is provided for generating a predetermined amount of reciprocable rectilinear vertical movement of the shuttle assembly through a predetermined range of motion. The transfer apparatus further includes means for selectively indexing the workpiece along a horizontal plane relative to the shuttle assembly. In particular, a second drive mechanism is provided for generating rectilinear horizontal motion of the workpiece. Programmable controller means is provided for selectively controlling the actuation of the first and second drive mechanisms.
Additional objects, advantages, and features of the present invention will become apparent from a reading of the following detailed description and the appended claims, taken in conjunction with the accompanying drawings.